html {
  height: 100%; }

body {
  font-family: 'Noto Sans TC', sans-serif;
  background-image: url(../images/poster.jpg);
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center;
  background-size: cover; }
  body .link {
    position: absolute;
    top: 64%;
    left: 24%; }
    body .link .btn-primary {
      padding: 15px 20px;
      font-size: 16px;
      border-radius: 30px;
      background: -webkit-linear-gradient(top right, #e80808, #0400ff);
      background: -o-linear-gradient(top right, #e80808, #0400ff);
      background: -moz-linear-gradient(top right, #e80808, #0400ff);
      background: linear-gradient(top right, #e80808, #0400ff); }
      @media screen and (min-width: 340px) {
        body .link .btn-primary {
          font-size: 17px; } }
      @media screen and (min-width: 340px) {
        body .link .btn-primary {
          font-size: 18px; } }
      @media screen and (min-width: 360px) {
        body .link .btn-primary {
          font-size: 19px; } }
      @media screen and (min-width: 375px) {
        body .link .btn-primary {
          font-size: 20px; } }
      @media screen and (min-width: 400px) {
        body .link .btn-primary {
          font-size: 21px; } }
      @media screen and (min-width: 414px) {
        body .link .btn-primary {
          font-size: 23px; } }
      @media screen and (min-width: 480px) {
        body .link .btn-primary {
          font-size: 27px; } }
